Puck Accelerator Device (A.K.A. PAD)
Rationale- I picked this theme for several reasons. One is that I love hockey a lot and have been playing pond hockey ever since I was six. I also saw ways to improve this sport and its practice methods. This machine does a task that I need practice with… one time shots. The Puck Accelerator Device was named so because first of all, it accelerates pucks, and second of all, it sounded cool and high-tech.
Forces and Motion- This machine involves a lot of motion physics. Speed is important to the prototype, because the speed of the puck needs to be just so. Velocity also is an issue, because the puck needs to go towards the launcher, not away. And acceleration matters. The faster the launch pedal accelerates, the faster the knocking board accelerates, which determines the speed of the puck launched. When I push the pedal down, that’s the pull of the machine. When I push the pedal, the wire pulls the board, which is a pull. Another pull is the pull of gravity on the puck stack. The momentum of the board is transferred into the puck it collides with, and since momentum is conserved, the puck goes out with nearly the same momentum. The reason it isn’t identical momentum is because of the friction involved. There is fluid friction (the air) and there’s sliding friction (the floor).
Newton’s Laws- The first law of motion is what keeps the puck still, it will stay motionless until acted upon by the unbalanced force of the moving board. The board keeps moving until it collides with the puck which is the unbalanced force. The second law decides the speed of the puck, which simply is, the more momentum the board has, the more momentum will be transferred into the puck. Acceleration depends on mass and force applied, and since all pucks are the same weight and size, the sole variable is how hard I press the pedal. The third law is forces act in pairs. This means that the harder the launch board pushes the puck, the harder the puck pushes off the board and the faster it goes.
Work- I do work on the machine, and in turn the machine does work on the puck, which gets launched. First, I work on the pedal, which in turn does work on the wire. The wire wraps around the pulley and then works on the launch board. This, finally, does work on the puck to launch it.
Efficiency Effort- I tried to make the machine more efficient by using these things: smooth, slippery material for the sliding, pulley wheels for the wire going around the bolt, and a bolt hinge for the pedal.
Machines- There are several machines involved in the machine and its purpose. I have two first class levers, one being the pedal, which is simply bent. The second one is the launch board. These were used simply to change direction of force. The pedal converts vertical motion into horizontal motion, and the launch board converts backward motion to forward motion. The pulley was also to change direction of force. These were better than the others simply because they weren’t as hard to make and that they were the only ones to make it possible and easy to make.
Energy Transfer- First, the energy is potential in all the moving parts. First, the launcher’s leg converts PE to KE, which in turn transfers PE to KE in the pedal, which pivots and pulls the wire. The energy is redirected around the pulley and to the board, which is pulled. The board’s energy allows it to pivot around the fulcrum and hit the puck, which is the last to convert PE to KE. But not all the energy stays in motion form. Some is converted into heat when the board rubs the floor and the wire rubs the pulley. Also, the hinges for the fulcrums create heat.
Improvements- One, I could use bearings in the fulcrums of the first class levers to create less friction between the boards and the bolts. I could also use a bearing pulley wheels to make the wire go around the bolt better. Third, I could use a wheel to lessen friction between the board and the floor. Other than that, I don’t know what else to improve on.
Questions???